The main objective of the project is to enable the optimization of preparation technology for special glasses. The results of measurements of electrical properties realized by the Slovak partner of the project will provide feedback to the main Czech applicant so that they can be modified conditions for the preparation of glass to reduce the concentration of defects and increase the homogeneity of samples. We will: prepare samples of the special glasses transmitting infrared radiation measure their electrical, dielectric and optical properties analyse results to investigate the influence of impurities and/or of dopants on these properties determine the correlation between chemical composition, stability of glass and the concentration of admixtures study the possibility of using methods of measuring the dielectric properties by thermally stimulated depolarization currents for the above purposes.